1. Field of the Invention
The current invention relates to a hold-down for securing a component to a circuit assembly and more particularly to a multiple fish hook hold-down for securing a connector housing to a printed circuit board.
2. Description of the Related Art
An apparatus to secure a connector to a printed circuit board is generally known as a hold-down. Prior art hold-downs at least temporarily secure a connector housing onto a printed circuit board, prior to or during soldering of electrical terminals mounted in the connector, by providing an interference fit. Usually, such an interference fit is caused by contact between a press-fit section of the connector housing and an inside wall of the fitting hole on the circuit board. These interference-fit hold downs, however, lack a sufficient amount of retention force, and consequently, they require a special seating tool to increase the retention force.
To improve on the retention force, U.S. Pat. No. 5,083,942 discloses a single fish hook hold-down for securing a connector housing to a circuit assembly. According to the '942 patent, a fish hook hold-down comprises an anchoring portion at one end, an attaching portion at the other end and an elongated portion between the two ends. The fish hook hold-down is firmly fixed to the connector housing by the attaching portion. In order to at least temporarily stabilize the connector housing on the circuit assembly, the fish-hook-like anchoring portion of the hold-down is inserted into a through hole on the circuit assembly. As the insertion takes place, the tip of the anchoring structure is urged against an inside wall of the through hole and anchors the hold-down to the circuit assembly. As a result, the single fish hook hold-down more securely holds the connector housing to the circuit assembly than the prior art interference fit hold-downs.
Despite the above desirable features, the hold-down disclosed by the '942 patent has at least three major areas for improvement. First, since the anchoring portion of the hold-down is at the opposite end of the elongated portion from the attaching portion and the anchoring portion must be firmly urged against the inner wall of the through hole on the circuit assembly, the attaching portion needs to be firmly and precisely positioned in the connector housing. Thus, the connector housing requires a particular chamber for accepting the attaching portion. Secondly, even though the hold-down is firmly held in the connector housing, the anchoring portion must be precisely aligned with the through hole in the circuit assembly. Any slight misalignment can prevent the anchoring portion from firmly engaging the inside wall of the through hole, and the connector housing is not secured to the circuit assembly. Lastly, even when the connector housing with the hold-down is precisely aligned and inserted with respect to the through hole on the circuit assembly, a single anchoring point per hold-down does not always yield a desirable amount of retention force for the circuit assembly. The current invention is directed to these and other imperfections and substantially improving over the above-discussed prior art. Thus, the objects of the current invention include at least the following.
It is an object of the current invention to provide a fish hook hold-down that has a higher tolerance for misalignment during insertion into a retaining through hole.
It is another object of the current invention to provide a fish hook hold-down that accommodates a simplified connector housing for retaining the hold-down.
It is yet another object of the current invention to provide a fish hook hold-down that yields a higher retention force.